Pi Ceti

Pi Ceti
Location of Pi Ceti (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Cetus
Right ascension 02h 44m 07.34928s[1]
Declination −13° 51′ 31.3130″[1]
Apparent magnitude (V) 4.238[2]
Characteristics
Spectral type B7 V[3] or B7 IV[4]
U−B color index −0.396[2]
B−V color index −0.130[2]
Astrometry
Proper motion (μ) RA: −8.62[1] mas/yr
Dec.: −9.07[1] mas/yr
Parallax (π)8.30 ± 0.21 mas[1]
Distance393 ± 10 ly
(120 ± 3 pc)
Absolute magnitude (MV)−1.16[5]
Orbit[6]
Period (P)2,722±14 d
Eccentricity (e)0.0±0.7
Periastron epoch (T)2444852 ± 29 JD
Argument of periastron (ω)
(secondary)		0.0°
Semi-amplitude (K1)
(primary)		4.33±0.25 km/s
Details[7]
π Cet A
Mass4.4±0.2 M☉
Radius4.3±0.3 R☉
Luminosity468 L☉
Surface gravity (log g)3.8±0.2 cgs
Temperature12,900±400 K
Metallicity [Fe/H]0.28±0.16[8] dex
Rotational velocity (v sin i)20.9±1.2 km/s
Age0.3+0.1
−0.1 Myr
Other designations
π Cet, 89 Ceti, BD−14 519, FK5 97, HD 17081, HIP 12770, HR 811, SAO 148575.[9]
Database references
SIMBADdata

Pi Ceti, Latinized from π Ceti, is the Bayer designation for a star system in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 4.238.[2] Observed to have an Earth half yearly parallax shift of 8.30 mas,[1] it is around 393 light years from the Sun.

This is a single-lined spectroscopic binary system with a nearly circular orbit and a period of 7.45 years. The fact that the system has a negligible eccentricity is surprising for such a long period, and may suggest that the secondary is a white dwarf that had its orbit circularized during a mass-transfer event.[6]

The primary, component A, is a normal B-type star[7] that has been given stellar classifications of B7 V[3] and B7 IV.[4] It appears very young – less than half a million years in age – and may still be on a pre-main sequence track. The star shows no magnetic field but it does emit an infrared excess.[7]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference GutierrezMoreno1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Buscombe1962 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Lacy1997 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Folsom2012 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Prugniel2011 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).